Laws About War
These verses deal with the matter of spiritual preparation for battle. Moses understood that people going into battle must first win the battle against fear in their own hearts and minds. Moses instructed the people that before going into battle against enemies whose numbers and military might were greater than their own (20:1), the priests were to speak to the warriors (20:2) and remind them not to be afraid for three reasons (20:4).
First, “the Lord your God is the one who goes with you.” The priests were to assure the warriors of the Lord’s presence with them in battle. God never intended for them to face their battles without Him.
Second, the Lord will “fight for you against your enemies.” The priests were to remind the warriors of the participation of the Lord with them in battle. While their enemies might have superior skilful numbers and superior provisions of horses and chariots, the Israelites had the omnipotent God fighting with them.
Third, the Lord will “save you.” The priests were to remind the warriors of the Lord’s power to protect them and give them victory in battle. The Israelites needed the Lord in battle. John Maxwell comments, “God never makes us so strong that we no longer need Him. Never.”
Refer to notes on Deuteronomy 7:17-26 for more information on preparation for battle.
Practical Consideration: God’s presence can give us the confidence to face life’s battles. Before going into battle, Israel’s soldiers were to be reminded that God would not only be with them but also would also fight with and protect them. This knowledge gave Israel’s soldiers confidence in going into battle. We too, can be assured that God is not only present with us but will also fight with us as we face life’s battles.
The officers were instructed to make certain (20:5a) that the men going into battle were not only qualified, but not subject to being distracted by personal matters (20:5b-7). Certain exemptions were granted to men who had not yet had the privilege of enjoying certain undertakings. These were allowed to return home. They were to complete their undertakings and so contribute to the stability of the land. Fearful men were exempted from going into battle because they might have a demoralizing influence on their fellow soldiers (20:8).
Read also Judges 7 regarding the reduction of Gideon’s army from thirty-two thousand men to three hundred. Maxwell notes, “Gideon and all of Israel learned that God counts hearts, not heads, when He wants a great work accomplished.”
These verses address the matter of military strategy. In cases where the Israelites were engaged in battles outside the borders of Canaan (20:15), they were to offer terms of peace to the inhabitants of the city (20:10). If the peace offer were accepted then the inhabitants were to become servants of the Israelites (20:11). If the peace offer were denied then the men of the city were to be executed (20:12-13) but the women and children spared (20:14).
In the case where the Israelites were fighting against cities within Canaan, absolutely no one was to be spared (20:16-17) lest any survivors lead the Israelites spiritually astray (20:18). Deuteronomy 20:19-20 give instructions regarding the use of trees in a siege. Fruit trees were to be spared (20:19) while non fruit-bearing trees could be used to make implements of war (20:20).